Microphone Position Validation via Acoustic Time Delay Comparison

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Solution Overview

Problem

Current methods for determining the position of a microphone in simulators, such as vehicle simulators, are inadequate as they rely on visual cues which are subject to individual interpretation and may require custom tripods that are obstructive and costly, leading to inconsistencies in sound test results due to variations in microphone placement.

Innovation Solution

A method and system using time delays between sound signals emitted by multiple speakers to accurately determine the microphone's position, where reference and test sound signals are played back with controlled time delays, allowing for precise matching of the microphone's position to a target location through comparison of actual and reference time delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If pictures are provided to guide microphone installation, then installation guidance is available, but positioning accuracy deteriorates due to individual interpretation

Engineering Contradiction:
Improveinstallation guidanceVSAvoidmicrophone positioning accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces visual mechanical guidance (pictures) with an acoustic field-based positioning system. Speakers emit sound signals that create an acoustic signature unique to the target position. The microphone captures these signals, and the system automatically determines positioning accuracy by comparing time delays and signal characteristics, eliminating subjective visual interpretation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If a custom fixed tripod is provided, then microphone positioning stability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemicrophone positioning stabilityVSAvoidtripod structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent enables the microphone to self-determine its position through acoustic signal processing. The device captures sound signals from multiple speakers, processes time delay information, and automatically identifies whether it is at the target position, eliminating the need for complex external positioning structures like custom tripods.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If a custom fixed tripod is provided, then microphone positioning stability is improved, but installation time increases

Engineering Contradiction:
Improvemicrophone positioning stabilityVSAvoidinstallation time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent replaces mechanical positioning structures with an acoustic field-based system. The microphone automatically determines its position by processing sound signals from speakers, eliminating the time-consuming process of manually setting up and adjusting custom tripods while maintaining positioning stability through acoustic feedback.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Adaptability or versatility

If microphone position varies, then setup flexibility is improved, but sound test reliability deteriorates due to dephasing

Engineering Contradiction:
Improvemicrophone placement flexibilityVSAvoidsound test reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the system continuously monitors the microphone's position by analyzing acoustic signals from speakers. When the microphone deviates from the target position, the system detects changes in time delays and signal characteristics, providing feedback to maintain positioning accuracy and ensure sound test reliability.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach ensures reliable and repeatable microphone positioning by providing a precise indication of match or mismatch, enhancing the accuracy and efficiency of sound tests without the need for custom tripods, thus improving the consistency of sound calibration and testing results.

Implementation Method 1

a first sound signal is emitted via a first speaker and recorded using the microphone at the given position. A second sound signal is emitted via a second speaker and recorded by the microphone

Methodology Applied
Scientific EffectSound propagation: Sound

Implementation Method 2

determining a propagation time of each signal and determining an actual distance between the microphone and each speaker using the speed of sound and the respective propagation time

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3546977B1Method and system for validating a position of a microphone
Publication Date: 2024.08.21 CAE INC
  • EP3546977B1 patent drawingFigure 1
  • EP3546977B1 patent drawingFigure 2~3
  • EP3546977B1 patent drawingFigure 4~5

AI summary

A method comprising: receiving a reference time delay between a first reference signal (40) emitted by a first speaker (32) and a second reference signal (42) emitted by a second speaker (34), each recorded by a microphone (36, 68, 154) having a target position; using the microphone positioned at an actual position, recording a first sound signal (46) emitted by the first speaker (32) and a second sound signal (48) emitted by the second speaker (34); determining an actual time delay between the first and second sound signals; comparing the actual time delay (Δt1) to the reference time delay (δt1); determining a match or a mismatch between the actual position and the target position for the given microphone; and outputting an indication of the match/mismatch.